Locking disk



Dec. 31, 1935. H. BENZING 2,026,454

LOCKING DISK Filed Jan. 9, i934 Patented Dec. 31, 1935 LOCKING DISK Hugo Benzinr, Dresden, Germany,

or to assign Aktiengesellschai't vorm. Seidei & Naumann.

Dresden, Germany 7 Application January 9, 1934, Serial No.

Germany January 10, 1933 lClaim.

This invention relates to a detachable spring disk for securing shafts and axles in machines and apparatus of a fine-mechanical kind against displacement in an axial direction or against rotation.

Disks have already been proposed which, by means of a central aperture, are placed over the shaft and fit into an annular groove, and are furnished with a resilient middle portion, which towards the side is bent out in serpentine fashion to form a spring.

These disks are incapable of use in connection with machines and apparatus of a fine-mechanical nature, and more particularly typewriters, calculating machines or the like, as owing to the small amount of space available the laterally bent resilient portion cannot be accommodated. Beyond this the groove into which the disk is fitted requires to possess a width which is greater than the thickness of the disk, as the latter when resiliently yielding loses its flat form. Its production is moreover only possible at the expense of a considerable amount of material, and requires a number of operations.

Detachable resilient disks have been suggested having a recess opposite the slot by which the cross section of the disk is weakened to such an extent that it becomes resilient to the same extent or in the same amount by which the slot is smaller than the central aperture. In this case, the resilient rectangular cross section has to become so small that it may execute this relatively large spring motion without undergoing a stress approaching the limit of elasticity. The spring force that can be obtained by such a small cross section and which forces the disk into the annular groove of the bolt, can only be very small. In order to remove this deficiency the present application provides for two adjacent recesses opposite the slot of the disk and extending outwardly from the central aperture, and also a projection of small width, smaller than that of the recesses, and located between said recesses, so that two separate resilient cross sections are formed each of which need give only to an extent representing a part of the total resiliency of the disk. The result is that the resilient cross sections may be made larger without being stressed beyond their limit of elasticity when giving.

The subject matter of the invention is illustrated by way of example in the drawing, in which Figs. 1-3 show diiferent forms of the locking disk.

Figs. 4 and 5 show a preferred form of embodiment of the arrangement in plan and in section,

Fig. 6 illustrates an example of the use of the invention. l

The disk It possesses a middle aperture b, corresponding with the cross-sectional form of the rod over which the same is to be placed. and a recess 0, so that arms 11 and e are formed, which are held somewhatapart by the natural resiliency of the disk. Since a spring disk of this nature may be bent only very little apart without exceeding the elastic limit, it is proposed accordl0 ing to the invention to weaken the material in the vicinity of the cross-section h, which is subjected to pressure and strain (bend) when the disk is applied, or also on either side thereof,

so that the cross-section where bending takes 15 the safety against excess of strain to twice theamount. It is possible to select the height of these cross-sections k, l in such a. manner that a strong resilient efi'ect is nevertheless obtained.

In order that the frequently very small spring disks may engage readily on the shaft, the aperture e thereof will preferably be made somewhat larger on the outside than the inner diameter of the groove or recess into which the disk fits. At the inner end, however, the same is somewhat narrower than this diameter, so that upon withdrawing the disk the inherent resiliency thereof requires to be overcome.

A spring disk of the kind described up to now is able to rotate readily on the shaft or axle. If the same is to remain tight on the rod, the same must be furnished with a preliminary stress in the fitted position. This may be accomplished by making the middle aperture b smaller whilst retaining the same radius of curvature in respect of the curves 1 and 9'. The cutting edge of the die is accordingly furnished in the vicinity of the contour lines I, g for example with a form as indicated in dotted lines in Fig. 4, which form at the same timeis also that of the stamping. In this manner the disk, after being slipped into position, cannot return wholly into the normal position, and is maintained under a certain stress, which takes efiect in the form of a corresponding clamping pressure.

The subject matter of the invention, in addition to the manner 01 use just described, may also be employed for transmitting small turning moments. For this purpose it is merely necessary on the one hand to couple the disk with the rotation of the shaft and on the other hand to connect the same with the body to be moved.

An example of this is illustrated in Fig. 6. The lug i is somewhat extended (indicated in broken line in Fig. 4), and may penetrate into a corresponding radial recess in the shaft 9. The extended lug may also be taken at right-angles out of the plane oi! the disk and project into a groove on the periphery of the shaft. For coupling the disk with the body 0 to be moved there may be provided in the disk a a bore 112, into which there is fitted a pin n, which at the same time may also penetrate into the body 0. Other operating methods are naturally also conceivable.

It will be understood that no restriction is made to the specific forms of embodiment illustrated in the drawing, which are quoted merely by way of presenting a disk composed of oppositely disposed 1o integral resilient sections, yieldable relative to each other, each of said sections being provided with a recess opposite the radial slot and central aperture defining an intermediate tongue element serving as an exact adjustment for the disk in 15 relation to the center of the shaft to which saiddisk is attached, portions of the walls of the central aperture engaging the shaft and acting as clamping jaws thereby preventing the disk from chattering on said shalt.

HUGO BENZING. 

